# Answer check — episode 81

Packing is 8 units per hour. Labeling and Setup have no defined rate because their hours are zero and blank respectively; their result cells stay blank. A blank result is not zero productivity. The original units and hours remain unchanged.

## Applicability

A blank in the result column represents missing or invalid hours in this fictional exercise. If zero hours is a real business state, decide separately how to report it. IFERROR can hide unrelated formula mistakes.

The practice example is fictional. Confirm the current control and result in your own permitted English-language application copy.